<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        *{
            margin: 0;
            padding: 0;
        }
        html{
            /* font-size: 100vw; */ 
            font-size: 26.666667vw;
        }
        body{
            /* rem布局一定要在body重置font-size大小 */
            font-size: 0.16rem;
        }

        .box{
            /* 页面可视区分成了100vw 和 100vh */
            width: 1rem;
            height: 1rem;
            background: skyblue;
        }
    </style>
</head>
<body>
    <div class="box">哈哈</div>
</body>
</html>